I’ve become interested in finding with greater precision how my body reacts in different circumstances. I had a story that I felt poorly after eating cheese. It was based on one period of my life and was entirely anecdotal. As I described in my post about my shift to a ketogenic diet, I had started eating more fats, to include cheese. And I felt great. This got me thinking about how many of these unexamined stories guide my behavior.
With that in mind I started looking at alcohol’s effect on waking mental calm and heart rate variability (HRV). I like a glass of wine or two in the evening. It is well documented that alcohol has a physiological impact. From quantified selfers looking at their Basis data to scientific studies there is a wealth of information on the physiological impact of alcohol. My question is how much can my body tolerate before it reduces my heart rate variability and mental calm.
What impact does having alcohol (or not) have on my morning HRV and mental calm?
What I Did
For thirty-three days on waking I measured my mental calm and heart rate variability while noting if I had had alcohol the night prior.
How I Did It
I would measure my mental calm using Muse EEG headset and my HRV using a Polar H7 heart rate belt that sent data to an app called the Heart Rate Variability Logger. All data went into a Google spreadsheet.
What I Learned
Drinking alcohol the night prior reduced average HRV and increased average Muse “% calm” score. After a night of boozing I was mentally more Zen but my nervous system was under increased load.
The Muse % calm readings were not visibly different between having had alcohol or not. The Pearson correlation (.12%) showed a negligible relationship between the calm readings and whether I had consumed alcohol the night prior.
My average % calm after having no alcohol was 36.4% and after having alcohol was 42.7%. Looking at the averages I appeared more calm after drinking. Because the scores did not correlate with consumption we can’t draw any real connection.
My HRV did correlate with consumption, with a Pearson correlation = -.306, a moderate negative relationship. There seems to be a connection with drinking alcohol and a lowered HRV was lower the following morning.
My average rMSSD the morning after a night of alcohol was 48.6. A morning after no alcohol the average was 62.1. A moderate correlation and a much lower average verified that HRV seemed to be impacted by alcohol.
But knowing that does not really give me any precision nor any guidance on how to change behavior. So my next study is to examine how much alcohol I can consume and not have my HRV drop. If I am going to enjoy a glass and don’t want to take an HRV hit the next day, how many glasses can I have? With this I will know my own tolerance and be able to guide my actions with better data.